Johnny Sexton conceded that ill-discipline let Ireland down in the Guinness Six Nations defeat to Wales in Cardiff.
A number of infringements cost Andy Farrell's side, most notably Peter O'Mahony's red card which left the Irish side down to 14 men for more than an hour.
Speaking at full-time Sexton, who will be assessed after departing the field of play 10 minutes from the end for a HIA following a head knock, admitted that while he was pleased with the resilience shown, Ireland conceded too many penalties.
But he also questioned why Wales centre Johnny Williams did not join O'Mahony in being sent off following a first-half challenge on Garry Ringrose.
"We regathered really well, I am proud of the boys, I am proud of the effort, proud of the position we put ourselves in," Sexton told BBC One.
"Ultimately, it came down to a few mistakes at key times and the rub of the green as well.
"There were a couple of decisions where we get red-carded, a high tackle that gets penalised versus one that doesn't. Apparently they looked at it.
"But Wales are a very good side and we've only ourselves to blame. We spoke about discipline earlier in the week and that let us down at key times, as well as some key unforced errors."
The match ended in bizarre circumstances when a wayward kick for touch from replacement Ireland fly-half Burns brought proceedings to an end. But Sexton defended his team-mate's error.
"As a 10, you've got to go for it and you've got to go and try and put it five metres out," Sexton said.
"Sometimes you miss, sometimes you get it and you're a hero but he did have to go for it because it's a big difference between going 10 metres out and five, it gives us a chance to score."
In contrast, Wales counterpart Alun Wyn Jones was relieved to hold on for victory.
"If you've been fortunate enough to pull this on (a Wales shirt), there's always pressure," said the Welsh captain.
"There was particular pressure after the autumn we had and I won't shy away from that.
"The game today probably told a story of what happens when you come under a pressure - but a positive pressure of of being a man to the good. We came through, thankfully."
